Volt-ampere-hour meter



Aug. 2, 1927. ,370

G. A. CHEETHAM VOLT AMPERE noun METER Filed Aug. 19. 1922 WITNESSES: INVENTOR a Z 4 I CueorseArthur Gheethom. l v

- ATTORNEY Patented Aug. 2, 1927.

cums-D STATES [PATENT ce-F resdis-oxen keratin EEETHAM, F. naNGHEsrnn, ENGL D. [ASSIGNOR 'ro W TING- Hops]: ELECTRIC a VANIA.

amilicaaon me-a mine is, 1922, Serial in.

My invention relates to alternating-current electric meters and particularly to kilovoltampere-hour meters.

One object of my invention is to provide BKa device ofthe above-indicated character v that shall operate accurately over a wider range of power fact'or changes than has heretofore been usual.

Another objectfof' inv invention is to providela kilovolt-ampere hour" meter that shall be simple and durable in construction, eco- -nomical to manufacture and effective in its operation. v

As is well known to those versed in the art, aninduction-type watthour meter? may be adapted pr compensated to read kilovoltampere-hours more or less'accu'rately over a variation ofphase angle of'about 44 be tween the voltage and the current. 'Forexample, such ain'eter maybe compensated to.

read with power factors ranging from unity to 0.72. lagging or from 0.72 lagging to 0.04% lagging or any intermediate power-factor over a range equivalent to a variation in phase angle of 44, an'd it may be similarly ;compensated for leading power factors.

Vith phase angles on either side of the range of44 for which themeter is compensated,

the meter disc'will rotate at a speed which is slower than thatnecessary for a true reading; as will be well understood.

Acc ordim to the present invention, a -plurality of wa tt-hour meters each compensated to readkil'ovolt ampere-hours over a differcut range of power-factors is employedand said meters are mechanically connectedtogethen'and to'an integrating train, in such manner that said train willalways" be actuated by the meter which is driven the fastest.

The meters are individually compensated so that one reads; correctlyfrom, say unity power-factor to .72 powert'fa'ct-or'lagging and the other one reads from .72' powerfactor lagging to .04 power 'factorlagging, so that the total range willbe from unity power'- factor to substantially zero power-factor. The meters may, of course be' compensated to read over any desired consecutive ranges of ower' factor.

" re 1 of thezicconipariying drawings is a ront elevational View of aportion of an instrument constructed in accordance with my invention, and A Figs. 2 and 3, are, respectively w'side'eh MANUFACTURING cdMrANY, A CORPORATION or PENNSYL von'r-iimrnnn nounMETER.

582,990, andin Great Britain August 20, 1921.

vat-ional. view and a plan View of the device shown in Fig. 1. l

Two single phase orpolyphase watt-hour meters, which are of the induction type and compensated to read kilovolt ampere-hours on. consecutive] ranges of phaseangle, are provided with the usual discs 1 and 2 mounted on shafts 3 and fl, respectively, carriedin bearings (not shown) in the usual manner. 7 Each shaft v is provided, at its'upper end, with a bevel wheel 5 engaginga bevel wheel 6 upon a Sliil-ff'Ol spindle 7 Theshaftsor spindles 7 are mounted in alinement with "one another in suitable bearings (not shown) and. are provided with bevel wheels8 at j their adjacent ends. -Tl1espindlesf7 are furlibel provided with bevel'wheels 9 engaging bevel wheels 10 upon the lower ends of parallel shafts 11' and 12, the upper ends of which are; provided, respectively, with pin-' ions 13'and 14. e M v A pair of bevel wheels .15 engage the bevel wheels Sand are carried i-n' a. ring or frame 16 tothus constitute a. differential gcarfineclianism. Thering or frame 16 is provided fwith a i notch 17 for purpose which will be hereinafter set forth. The 'pinions 13and 14 are adapted to engage, re spectively' and alternately, toothed wheels 18 and 19, according to which. of the meters is rotating the faster. The wheels 18 and19 are carried. in Ta bracketf20 which is pivoted to a fixed member 21 on a vertical pin 22. The toothed wheels 18 and 19 areadapted'to engage a fixed pinion 23 (Figs. land 2) whichl is permanently in engagement with a toothed wheel 24 (Fig. 2) connected toany convenient form of integrating mechanism n0tm shown). through a: pinion 25.

. "A fork 26, on the underside of the pivoted bracket 20, is engaged by a pin or rodl27 carriedby an upwardly extending lever 28 which is pivoted to a fixed pin ormember 29. A spring 30 is connected at one end, to the pin 27 and; at the other end, to one endi31 of a secondllever 32 that ispivote'dt0 afixed .pin '33. The other arm 34.jof thelever132 is provided with a-pin or; roller 35 (Fig. 1) adapted to co-operate with themotch 17 in I. the ringer frame 16 of the differential gear fimechanism. The pivot axes of the levers 28 'and 32 he in'a vertical plane so that the after the manner er a toggle link.

be compensated; or calibrated to read a range.

In operation, assuming that the spindles or shafts 3 and 4 of the respective meters are rotating in the counter-clockwise direction, as viewed from above, and that the shaft 3 of the left-hand meter ismoving the faster, the pinion 13 is connected to the integrating mechanism, the power factor of the circuit to which the meters are connected being, for example, between unity andO/FQ lagging. When the power factor of the cir- "cuit drops below 0.72 lagging, thatis, to

a figure within the rangeofthe right-hand *meter, the latterwill rotate the faster, while thespeedof rotation of the left-hand meter wiIl'decreaSeQ The right-hand bevel wheel 8 will then' rotate faster than the left-hand:

bevel wheel 8 ,'with the result thatthe ring *or frame. 16 will rotate in the clockwise direction (Fig 2). j 'As the ring or frame rotates, thepin or roller 35 will'fall into the notch'or' depression 17 an d,'as the'rotation 0f thering .16 continues, the lever 32 willbe turned about its pivot 33. Thus, the spring will be extended until the direction of the pullof the spring has passed across the pivot ofthe lever28, whereupon, the latter will be "moved over'its dead center to rock the Q frame 20 about'the axis ofthe pin 22. This movem'entjcauses the wheel 19 to engage the engage the pinions 13 and 23. The right- "hand meter will then operate the integrating "mechanism. 'The ring or frame 16 will conpinions 14 and '23 and the wheel 18 to distin'ueto' rotate'in the same direction, having no effect upon the lever 32 until the direction otrotation is again reversed. This reversal will; occur when the left-hand meter rotates faster than the right-hand meter. The

lett-hand meter will rotate faster than the right-hand meter when the'power factor rises to within the range to which the lefthand meter is adjusted andcompensated to 1 read.

In the arrangement above described, the mechanical portions of the meters areof fixed construction and relation. The calibration or compensation thereof is effected by means of impedance comprising suitable r inthelart." r.

The left han'd combinations of reactances and resistances, as will be well understood by those skilled fthat the'disc will standwith the current lagging the volts'by 120 instead of 9001 there nmfibethesaine percentage error at power 1 factors of unity and 0.72 lagging for each y element! \Vhen this has been done, the f meter is adjusted to be 3.8% slow: at unity power: factor.

of" power-factor corresponding to 44 of 1 phase angle, on either side of. unity; power factor,-or'to read entirely for leading power ,1 factors. 5

the

meter may be so adjusted.

It will be understood thatthe meters may:

The term higher speed signifies the meter disc which is rotating the faster in the positive direct-ion, that is, algebraically. Thus, if the meters are running backwards,

the disc rotating at the higher speed is in reality that which is running slower in the reverse direction.

While I have shown and described a par- .ticular form of myinventirm. changes may be effected therein without departing from the spirit andzscope thereof, as set'forth in the appended claims. A

I claim as my invention:

1. In an instrument, the combination with an "indicating means, of a plurality of ac: tuating means therefor accurately operative over. diil'erent. ranges of values of a quantity to be measured, and means including a gear mechanism andfa shifting device for the gear mechanism for lselectively connecting said actuating means to "said indicating means in accordance with a change in the value of said quantity from one of said ranges to another.

2.. In'an electric meter, the combination with an integrating mechanism, of a plurality of volt-ampere-hour. meters severall compensated to operate accurately over di ferent ranges of power-faotor changes, and

aheans, including gear mechanism and a shifting device for the gear mechanism, for a selectively connecting said volt-ampere-hour meters to the mtegrating mechanism.

- 3. In a meter mechanism, the combination with an integrating device having a primary gear member, of a movable structure,

a plurality; of 'gear members carriedby movable structure for selective; engagement with 531d prnnary gear member, a plurality of actuating shafts, gearmechanisms directly connected between. said selective gear members and said shafts an over-the-center device. for moving said movable structure and aditl'erentiahdevice connected between said shafts for actuating saidthe indicating device.

5. The romluination with a plurality of meters adapted tot operate accurately betweenpredetermined different ranges of'valuesofa quantity to be measured, indicating means, and a planetary gear system actuated by'the meters for controlling theconnectiouof the meters to theindicating device? V .In ,testimony whereof, I hairs hereunto subscribed .my name thisl 'secondday, of

GEORGE AR'iriuReHEiarHAM 

